Various kinds of paste-foamed materials and calendered films comprising mainly of polyvinyl chloride (PVC) resin have conventionally been employed as resin films for interior decoration materials (especially wallpaper). Wallpapers employing these PVC resins have problems in that chloride gas is generated when the wallpaper is disposed or in fires and environmental pollutions such as an indoor pollution is caused due to bleeding of the plasticizer. Thus, to solve these problems, wallpaper films employing polyolefin and paste-foaming methods employing polyolefin resin have recently been developed.
Further, in order to utilize these resin films as wallpapers, various materials have been provided as backing on the back side of the resin film or, in the case of tack paper-type wallpaper, a pressure sensitive adhesive or the like is applied. When applied directly to the wall or gypsum board, an adhesive (or paste) has conventionally been applied. Natural paper has typically been employed as the backing material since it shows good adhesiveness (strength) to adhesives and agglutinants, and is easy to dry. However, when natural paper of a composition differing from that of the resin material in the wallpaper is employed as backing, there is a problem in that wallpaper that is peeled-off for replacement cannot be recycled as is. Before recycling, the resin material and the paper backing must be separated. This separation is difficult and has proved to be problematic.
In tack paper-type wallpaper having a pressure-sensitive adhesive comprising a synthetic resin as a main component on its back side, it is also difficult to separate the pressure-sensitive adhesive from the resin material. Thus, if it is tried, a large quantity of pressure-sensitive adhesive remains adhering to the resin material. During recycling, the resin material with the pressure-sensitive adhesive undergoes heat decomposition and generates extraneous substances, and the fluidity of the resin changes greatly. These changes cause a quality problem.
Recently, to solve these problems, wallpapers devised to permit the separation of the wallpaper resin material and the backing (natural paper) have been proposed. For example, Japanese Unexamined Patent Publication (KOKAI) Heisei No. 6-173200 proposes a wallpaper that is obtained by forming a coating layer mainly comprising water-soluble polymer and a PVC resin-based or vinyl acetate-based synthetic binder on backing paper and laminating PVC resin thereon. The PVC resin can be separated from the backing paper by soaking the wallpaper in a hot water or an alkaline solution with stirring. Japanese Unexamined Patent Publication (KOKAI) Heisei No. 11-293600 proposes a wallpaper in which a PET film, PP film, or the like is laminated between the backing paper and a foam gelled PVC material. However, since there needs an additional step of separating the backing paper when using either of these wallpapers, there are problems in that the cost of recycling is increased and in that the quality of the recycled resin material drops, rendering these wallpapers impractical. Thus, disposed wallpaper is still being mostly buried or incinerated, and not recycled.
In light of these problems of prior art, the present invention has for its object to provide a multilayered-stretched resin film affording good suitability for printing and embossing, having good coating properties without backing paper or pressure-sensitive adhesive processing, peeling easily off the wall or board in a recyclable manner, and being useful as a single-material wallpaper.